A cam rotates on a drive shaft and generates reciprocating motion when another structure is in contact with the circumferential surface of the cam. If the drive shaft is fixedly mounted, the other structure rides on the circumferential surface of the cam and is referred to as a “cam follower” or, simply, a “follower”. If the drive shaft is movable (e.g., because the drive shaft is mounted on a movable structure), the circumferential surface of the cam may bear against a stationary structure, and the cam generates reciprocating motion in the movable structure and the cam, together. Regardless of whether the drive shaft is stationary or movable, rotation of the cam can lead to frictional wear of the circumferential surface of the cam and of the follower or other structure in contact with the cam.
It is the general object of this invention to provide improvements to cams and followers.